Climate controlled headgear apparatus

ABSTRACT

A headgear apparatus having a shell, an air flow structure, a thermoelectric system, a connector, and a condensate wick. The air flow structure is coupled to the shell and the thermoelectric system is configured to produce a stream of air. The thermoelectric system has a housing having at least one air inlet, a first and a second air outlet, a least one blower and at least one thermoelectric heat pump. The first air outlet provides the stream of cooled air to the air flow structure and the second air outlet vents hot air produced by the heat pump to outside the apparatus. The connector is configured to connect the first air outlet of the thermoelectric system housing to the air flow structure and the condensate wick is configured to collect condensation formed by the heat pump and evaporate the collected condensation using the hot air produced by the heat pump.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent application Ser. No. 16/486,492, titled “Climate Controlled Headgear Apparatus,” filed Aug. 15, 2019, which claims priority under 35 U.S.C. Section 119(e) to U.S. Provisional Patent Application Ser. No. 62/459,563 filed Feb. 15, 2017 entitled “Air Conditioned Helmet, (ACH) & Convective Headgear,” along with PCT App. No.PCT/US18/18260, filed Feb. 15, 2018, of the same title, the contents of which are incorporated herein by reference in their entirety.

BACKGROUND

There are many situations, both work oriented and sport, in which the wearing of a helmet or other headgear is necessary or highly desirable. Exemplary of but a few instances where wearing a helmet is required include motorcycling, cycling, and industrial/construction. Considerable discomfort can result from wearing a helmet or headgear, especially the full-face type, for even a short period of time particularly in warm or humid weather. Even outdoor events such as sporting events or otherwise, where persons wear hats for a long period of time could be uncomfortable.

Considering that the scalp is the most efficient and practical place to remove heat from the human body, a need exists to provide a lightweight, compact, and affordably priced sub-ambient temperature scalp cooling helmet and convective headgear technology.

SUMMARY

The present invention satisfies this need. The present invention is directed to a headgear apparatus comprising a shell having an inner surface and an outer surface, an air flow structure coupled to the inner surface of the shell, and a thermoelectric system configured to produce a stream of air.

The thermoelectric system is coupled to the shell and comprises a housing having at least one air inlet, a first air outlet and a second air outlet, a least one blower, at least one thermoelectric heat pump disposed within the housing, between the air inlet and the air outlets, and a condensate wick disposed within the housing, below the blower and heat pump. The first air outlet provides the stream of cooled air to the air flow structure and the second air outlet vents hot air produced by the heat pump to outside the apparatus. The condensate wick is configured to collect condensation formed by the heat pump and evaporate the collected condensation using the hot air produced by the heat pump.

The thermoelectric system can have a plurality of blowers and a plurality of heat pumps within the housing, and the housing can removably couple to shell.

The apparatus can further comprise a thermal insulation layer disposed between the inner surface of the shell and the air flow structure and/or an impact absorbing layer disposed between the inner surface of the shell and the air flow structure.

The air flow structure layer can comprise tubular spacer fabric and/or radiation cross-linked closed cell foam.

The apparatus can have a controller for controlling the thermoelectric system and there can be an air filter positioned proximate the air inlet of the thermoelectric system for filtering air entering the air inlet.

Optionally, the apparatus can have a connector that is configured to connect the first air outlet of the thermoelectric system housing to the air flow structure.

DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings.

FIG. 1 illustrates a basic pattern for a convective air flow structure layer for use in headgear.

FIG. 2 is a side elevation view of a thermoelectric air to air headgear heat pump.

FIG. 3 is a cross-sectional view of a headgear having an extra, ultra-light weight configuration with thin thermal external ambient heat insulation and a gusset at the rear to attach to a convective system.

FIG. 4 shows an additional ultra-light weight convective headgear design depicting an outer shell, an air flow structure layer, a thermal insulation layer, and an optional pad for optional Velcro® fastener for a convective system.

FIG. 5 is a side elevation view of a bicycle air-conditioned helmet having features of the present invention.

FIG. 6 is a front perspective view of the bicycle air-conditioned helmet of FIG. 5.

FIG. 7 is a rear perspective view of the bicycle air-conditioned helmet of FIG. 5, wherein a rear cover has been removed and the thermoelectric system is not installed.

FIG. 8 is an additional rear perspective view of the bicycle air-conditioned helmet of FIG. 5, wherein a rear cover has been removed and the thermoelectric system is installed.

FIG. 9 is a rear elevation view of the bicycle air-conditioned helmet of FIG. 5.

FIG. 10 is a front perspective cross-sectional view of the bicycle air-conditioned helmet of FIG. 5.

FIG. 11 is cross-sectional side view of the bicycle air-conditioned helmet of FIG. 5.

FIG. 12 is a skin temperature chart that measures moderate ambient air temperature, which shows the thermoelectric convective headgear cooling function versus ambient temperature.

FIG. 13 is a chart of skin temperature as a function of ambient temperature which depicts the skin temperature on different parts of a nude person measured at different ambient temperatures.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As used herein, the following terms and variations thereof have the meanings given below, unless a different meaning is clearly intended by the context in which such term is used.

The terms “a,” “an,” and “the” and similar referents used herein are to be construed to cover both the singular and the plural unless their usage in context indicates otherwise.

As used in this disclosure, the term “comprise” and variations of the term, such as “comprising” and “comprises,” are not intended to exclude other additives, components, integers ingredients or steps.

All dimensions specified in this disclosure are by way of example only and are not intended to be limiting. Further, the proportions shown in these Figures are not necessarily to scale. As will be understood by those with skill in the art with reference to this disclosure, the actual dimensions and proportions of any system, any device or part of a device disclosed in this disclosure will be determined by its intended use.

Teachings relating to the air conditioned helmets disclosed in U.S. patent application Ser. No. 11/252,089 filed Oct. 17, 2005 entitled “AIR CONDITIONED HELMET APPARATUS” which issued as U.S. Pat. No. 7,827,620 on Nov. 9, 2010, and U.S. patent application Ser. No. 10/601,964 filed Jun. 23, 2003 entitled “AIR CONDITIONED HELMET APPARATUS” which issued as U.S. Pat. No. 6,954,944 on Oct. 18, 2005, may be employed herein and the disclosures of which are incorporated herein by reference in their entirety.

Referring now to the drawings, FIG. 1 illustrates a basic pattern for a convective helmet interior air flow structure 170 (preferably tubular spacer fabric or “TSF”), having an air inlet 114 (air inlet 114 shown in profile as a dashed line for clarity), a lower rear edge air seal 172 if a neck roll is not used, and an insulation layer 150, which preferably is made from Voltek Volara®, being about 0.031 inches to about 0.062 inches thick and about 2 to 4 lb./ft³ to prevent cold spot formation where air enters the helmet. If the air flow structure 170 is used in a helmet that has insulation, the insulation is positioned against an interior surface of the helmet, and the air flow structure 170 is positioned against an interior surface of the insulation, such that air flow structure 170 is proximate the wear's scalp. The dashed line of air inlet 114 shows the approximate air entrance duct on the side of the air flow structure 170 that is opposite of the side of the air flow structure 170 is proximate the insulation. The air flow structure 170 comprises a plurality of woven, hollow tubes that permit air to flow therethrough. The air flow structure 170 can be cut with a computer-controlled laser. FIG. 1 shows the basic approximate pattern for the air flow structure 170 that provides a maximum internal area coverage in one piece before folding and inserting the structure 170 into a helmet or other piece of headgear. The pattern shown in FIG. 1 allows for proper orientation of tubes within the structure 170 such that air can flow through the tubes even when the structure 170 is folded and placed into a headgear. This air flow structure 170 may also be used in a cap or hat for running, jogging, medical purposes, etc., when inserted into a suitable shell, and the shell may be rigid or flexible. Different types and shapes of headgear and helmets may entail variations in this basic pattern 170 for optimal fit and air flow. When formed into the interior of a helmet, the pattern 170 shown in FIG. 1 allows edges A and B to line up with each other, facilitating a smooth interior surface and continuous air flow through the tubes from the entrance at the rear across the top and also along the full length of the sides for complete air flow coverage of the user's head. Air output 173 allows the air to blow/discharge into the face area.

The insulation foam layer 150, preferably Voltek Volara®, approximately 1-2 mm thick, with closed cells, is also shown in the area proximate the entrance of temperature modified air, but on the opposite side facing the user's head, to prevent a cold spot from forming at the back of the user's head and neck in cooling mode. The dashed line across the bottom of the figure represents the edge air seal 172, which is a soft molded piece, made of urethane, silicone, or other appropriate material, configured to reliably block air flow out of the air flow structure 170 in that region. Optionally, the edge air seal 172 can comprise a neck pad, or neck roll, that is modified to envelope the bottom edge of the air flow structure 170 and cover the area inside the air flow structure 170 opposite the air inlet to the air flow structure 170, to prevent temperature modified air from leaking out of the lower edge of the air flow structure 170 and, taking the place of the Volara® or other insulation, to prevent the formation of a cold spot at the back of the user's head/neck where temperature modified air enters the air flow structure 170.

Referring now to FIG. 2, there is shown a sectional side elevation view of a thermoelectric system 174. The thermoelectric system 174 is an air-to-air headgear thermoelectric heat pump that has a condensate management system. The condensate management system comprises an optional filter 175, at least one blower or fan 176, at least one blower adapter 177, and at least one Thermoelectric device 178. FIG. 2 shows the thermoelectric system 174 that has a hot side in cooling mode 179, a cold side in cooling mode 184, at least one condensate wick 181, and an air barrier 182. Arrow 180 is the warm/hot air existing to the ambient air (which can also contain any vaporized condensation) and arrow 183 is the cooled air that is blowing into the helmet/air flow structure 170 through opening 114.

The thermoelectric system 174 is unique in that the wick 181 traverses both the cold side 184 and the hot side 179 at the bottom of the assembly where cold air enters the headgear and warm air from the hot side 179 vents to the outside, ambient air. The purpose of the wick 181 is to collect condensate that drips down from the cold side 184 of the heat exchanger in humid weather and transport the collected condensate under a tightly fitting air barrier 182 that separates the two air streams 180, 183, over to the hot side 179 where it is evaporated away by the hot rejector air venting to ambient (stream 180). This condensate management system 174 prevents condensation produced during cooling in humid weather from dripping out of the helmet cooling system onto the user's neck or back, thus eliminating the distraction of the dripping water and making for a better, more comfortable, product from the user's point of view. The wick 181 can be secured in place with adhesive so that it does not shift while the user is wearing the headgear.

Referring now to FIG. 3, there is shown a detailed view of the different layers of material inside an embodiment of the air-conditioned headgear of the present invention. This can include welding, grinding, PAPR, and other types of convective helmets and caps, such as jogging/running caps, that don't require an impact absorbing layer and instead feature a thermal insulation layer to maintain high thermal efficiency. The thermal insulation layer may be made of conventional molded EPS, (Expanded Polystyrene), Volara®, or other closed cell foam or other high R-factor insulation material, with a thickness of between about 0.05 inches to about 0.125 inches for minimum helmet size and weight with good thermal performance.

In FIG. 3, the ACH 950 comprises shows an outer shell 951, an air flow structure 952, a connector 954 for connecting the thermoelectric system 174, a thermal insulation layer 958, an interior trim layer 956, and a lower edge seal 957. The interior trim layer 956 is a cover for the air flow structure 952 and is air permeable to allow air to pass from the air flow structure 952, through the interior trim layer 956, and onto the users' scalp. The lower edge seal 957 is a soft molded piece, made of urethane, silicone, or other appropriate flexible airtight material, configured to reliably block air flow out of the air flow structure 952 in that region.

Optionally, the ACH can have a non-slip surface 953 on an outside surface of the outer shell 951 to provide a surface for which an adjustable head strap such as a conventional hardhat head strap, for example, can grip.

The connector 954 for connecting and supporting the thermoelectric system 174 can be integrally molded into/as part of the outer shell 951 or separately molded and bonded to the outer shell 951. The purpose of the connector 954 is to provide a length of air duct to support the thermoelectric system 174 mounted to the rear of the outer shell 951.

In FIG. 3, the traditional, relatively thick and heavy impact absorbing layer that can be positioned between the outer shell 951 and the air flow layer 956 has been replaced with a thin lightweight thermal insulation layer 958, and 1123 in FIG. 4, which may be EPS, Voltek Volara®, or another suitable thermal impedance of about 1.5 mm to about 4 mm in thickness. This permits reduction in non-safety headgear/cap size, weight, and cost in non-vehicle related applications such as running and jogging, in addition to welding and grinding, for example, while maintaining high thermal efficiency by minimizing heat leak into the headgear cooling air.

Referring now to FIG. 4, there is shown an ACH (a preferred embodiment of a running cap) that comprises an outer shell 1120, an air flow structure 1121, a convective system support connector with short air duct 1124, a thermal insulation layer 1123, an interior trim layer 1125, and a lower edge air seal 1126, with cold spot insulator, preferably Voltek Volara®, approximately 1-2 mm thick. The ACH also has an optional pad 1122 for optional Velcro® fastener for removably coupling the thermoelectric system 174 thereto.

Referring now to FIGS. 5-11, there is shown an additional application of the air flow structure 170 in a bicycle helmet 1170. Bicycle helmets are generally much lighter than motorcycle and automobile helmets because of the much lower speeds encountered with bicycles and because a heavy helmet would place more of a load on the bicycle rider. Bicycle helmets may have a rigid molded foam impact absorbing layer similar to motorcycle and automobile helmets or may not have a foam layer at all. Optionally, bicycle helmets can have a chopped and bonded composition layer instead, with a hard molded shell.

The bicycle air-conditioned headgear (“BACH”) 1170 has a front section 1175, and a rear section 1176 which protects the front, back and sides of the head of a wearer. The BACH 1170 has a helmet shell 1173 and a removable rear cover 1171 which is attached to the helmet shell 1173 through the use of attachment means such as one or more screws 1172. The rear cover 1171 has a plurality of ambient air inlet vents 1174.

FIG. 7 illustrates the BACH helmet 1170 that is partially disassembled showing the internal structure 1178 which surrounds and supports the thermoelectric device/air cooling system 1180 as shown in FIG. 8.

FIGS. 10 and 11 are cross-sectional views of the BACH 1170 where the thermoelectric air cooling system 1180 can be seen in more detail. The thermoelectric system 1180 has at least one filter 1181 and at least one fan or blower 1182 which has an air duct 1183 for injecting temperature controlled/cooled air into the helmet 1170. The thermoelectric system 1180 can be mounted to the helmet under a removable cover 1171 having at least one air inlet opening 1174, as shown in FIGS. 5, 7, 8 and 9. Optionally, each air inlet opening 1174 can have an air filter positioned within, inside, or behind each opening 1174. The filter can be made of any appropriate air filter material, however a preferred material is woven polypropylene fibers that function electrostatically to attract and retain particulates, keeping the interior of the helmet cleaner over time in addition to keeping the heat exchanger fins in the convective system cleaner and more efficient over time. The air filter may be vacuumed periodically with a brush attachment.

Lab tests have showed a 51% improvement in exercise endurance in warm weather when the subject's head was intermittently sprayed with water, providing an unsophisticated form of evaporative cooling. As the headgear of the present invention is more efficient than that basic form of evaporative cooling, more than a 51% improvement in endurance can be achieved. This greater percentage of improvement is partially due to the fact that the headgear of the present invention utilizes thermoelectric cooling (via the thermoelectric system 170, 1180). The thermoelectric system 170, 1180 does not require the weight and bulk of water to achieve its cooling function, and it will not run out of water or need to be refilled in order to continue its cooling function. Additionally, thermoelectric system 170, 1180 provides a substantially consistent cooling function regardless of ambient humidity, whereas evaporative cooling performance is significantly affected by ambient relative humidity.

An important feature of the air flow structure 170 when applied to bicycle helmets, in addition to an approximate 51% improvement in endurance in warm weather because of the head cooling, is that a full-face type bicycle ACH provides cooled air for breathing, which increases the overall body cooling effect for a potentially even greater improvement in endurance beyond the 51% found in laboratory tests with evaporative head cooling only. Also, because the bicycle ACH does not need large vent holes like the average ambient air ventilated bicycle helmets of the prior art, the bicycle ACH of the present invention offers better protection because it covers the head completely, whereas most standard bicycle helmets actually only offer approximately 50% head coverage in order to provide minimum heat retention. That configuration only allows ambient air to impinge on approximately 50% of the user's head area, resulting in a relatively low level of body cooling, if any, especially in warm weather when ambient air is near, at, or above skin temperature.

FIGS. 12 and 13 illustrate how the sub-ambient air cooled headgear (ACH of the present invention) maintains a useful air dT over a wide range of ambient air temperatures, when properly designed, with a reduction in efficiency, or Coefficient of Performance, for the thermoelectric Peltier system, as ambient temperature drops, resulting in a significant reduction of, or the elimination of, overcooling at low ambient air temperatures while providing a meaningful dT at the highest ambient air temperatures, and without the need for a control system that increases headgear complexity, cost, weight, and bulk.

FIG. 12 is a skin temperature chart that shows the change in temperature ΔT for skin temperature 1602, ambient air temperature 1604, and ACH air temperature 1606.

A=Moderate ambient air temperature. Ambient below head skin temperature. ACH air temperature is below ambient and well below head skin temperature.

B=High ambient air temperature. Ambient is approximately equal to head skin temperature. ACH air temperature is well below both ambient and head skin temperatures.

C=Very high ambient air temperature. Ambient is well above head skin temperature. ACH air temperature is further below ambient and below head skin temperature. As ambient air temperature rises, ACH COP, (Coefficient of Performance), increases, maintaining a ΔT, or margin of ACH air temperature below ambient and head skin temperatures, providing cooling thermal transfer from head skin to ACH air up through very high ambient air temperatures.

As ambient air temperature drops, ACH COP drops, reducing ACH air dT below ambient air temperature, tending to prevent overcooling at lower ambient air temps. Ventilation mode air is the same temperature as ambient air. Normally, average body skin temperature varies by approximately 6.5° F. between ambient temperatures of 73° F. to 93° F. Normally, head skin temperature varies by approximately 3.5° F. between ambient temperatures of 73° F. to 93° F.

FIG. 13 is a chart of skin temperature as a function of ambient temperature which depicts the skin temperature on different parts of a nude person measure at different ambient temperatures. (Adopted from B. W. 1982, Thermal Comfort, Technical Review, Bruel & Kjaer). The chart shows that the temperature of the head varies less than 3° C. of a range of ambient temperature between 23 and 34° C.

It should be noted that the EPS foam or other impact absorbing structures or systems shown in this disclosure are normally found in helmets intended for transportation use. Other applications of the above disclosed technology may not include a foam impact absorbing layer, in which case the disclosed features of the embodiments will be applied without the foam impact layer. It should also be noted that the inside of any helmet in which the disclosed embodiments is employed is best made with a smooth continuous surface, however it is possible to secure the TSF, or other air flow structures, to a suspended inner liner, such as that found in helmets used in welding, grinding, and in the construction industry, by using a thin wall, lightweight supporting cap or hat to support the air flow structure. The cap or hat may be made by vacuum forming, blow molding, injection molding, hand layup, etc.

The solutions of the embodiments disclosed herein can be applied equally well to the lightweight bicycle helmets that are well known today. Bicycle helmets are molded mostly or entirely in foam, sometimes with a thin plastic veneer over the foam. They also usually have lots of openings to reduce heat retention on essentially the top and upper sides of the head.

The present invention has the following advantages:

Clinical trials have proven that head cooling in warm and hot ambient environments can increase physical endurance by over 50%, which has significant potential value for athletes and others who desire to experience greater comfort and/or improved physical performance in warm and hot ambient temperature conditions. The ACH of the present invention achieves, if not exceeds, this 50% increase in endurance.

The ACH of the present invention can be lightweight and affordable and can result in compact head cooling headgear (ACH) that can be used at sporting and athletic events and training, and everyday activities conducted in warm and hot environments, both indoors and out.

In this regard, the foregoing description is presented for purposes of illustration and description. Furthermore, the description is not intended to limit the preferred embodiments to the form disclosed herein. Accordingly, variants and modifications consistent with the following teachings, skill, and knowledge of the relevant art, are within the scope of the preferred embodiments. The embodiments described herein are further intended to explain modes known for practicing the preferred embodiments disclosed herewith and to enable others skilled in the art to utilize the preferred embodiments in equivalent, or alternative embodiments and with various modifications considered necessary by the particular application(s) or use(s) of the preferred embodiments. 

What is claimed is:
 1. A headgear apparatus comprising: a) a shell having an inner surface and an outer surface; b) an air flow structure coupled to the inner surface of the shell, the air flow structure comprising a tubular spacer fabric; c) a thermoelectric system removably coupled to the outer surface of the shell, the system configured to produce a stream of cooled air and comprising a housing having: i) at least one air inlet; ii) a first air outlet and a second air outlet; iii) a least one blower; iv) at least one thermoelectric heat pump disposed within the housing, between the air inlet and the air outlets; and v) a condensate wick disposed within the housing, below the blower and heat pump, the condensate wick configured to collect condensation formed by the heat pump and evaporate the collected condensation using the hot air produced by the heat pump; and d) a connector configured to removably connect the first air outlet of the thermoelectric system housing to the air flow structure; wherein the first air outlet provides the stream of cooled air to the air flow structure and the second air outlet vents hot air produced by the heat pump to outside the apparatus.
 2. The apparatus of claim 1, wherein there are a plurality of blowers and a plurality of heat pumps within the housing.
 3. The apparatus of claim 1, wherein the apparatus further comprises a thermal insulation layer disposed between the inner surface of the shell and the air flow structure.
 4. The apparatus of claim 1, wherein the apparatus further comprises an air filter positioned proximate the air inlet of the thermoelectric system for filtering air entering the air inlet.
 5. The apparatus of claim 1, wherein the apparatus further comprises a controller for controlling the thermoelectric system.
 6. The apparatus of claim 1, wherein the apparatus further comprises an impact absorbing layer disposed between the inner surface of the shell and the air flow structure.
 7. A headgear apparatus comprising: a) a shell having an inner surface and an outer surface; b) an air flow structure coupled to the inner surface of the shell; c) a thermoelectric system configured to produce a stream of air, the thermoelectric system disposed along the outer surface of the shell and comprising a housing having: i) at least one air inlet; ii) a first air outlet and a second air outlet; iii) a least one blower; iv) at least one thermoelectric heat pump disposed within the housing, between the air inlet and the air outlets; and v) a condensate wick disposed within the housing, below the blower and heat pump, the condensate wick configured to collect condensation formed by the heat pump and evaporate the collected condensation using the hot air produced by the heat pump; and d) a connector configured to connect the first air outlet of the thermoelectric system housing to the air flow structure; wherein the first air outlet provides the stream of cooled air to the air flow structure and the second air outlet vents hot air produced by the heat pump to outside the apparatus.
 8. The apparatus of claim 7, wherein there are a plurality of blowers and a plurality of heat pumps within the housing.
 9. The apparatus of claim 7, wherein the apparatus further comprises a thermal insulation layer disposed between the inner surface of the shell and the air flow structure.
 10. The apparatus of claim 7, wherein the apparatus further comprises an air filter positioned proximate the air inlet of the thermoelectric system for filtering air entering the air inlet.
 11. The apparatus of claim 7, wherein the apparatus further comprises a controller for controlling the thermoelectric system.
 12. The apparatus of claim 7, wherein the apparatus further comprises an impact absorbing layer disposed between the inner surface of the shell and the air flow structure.
 13. The apparatus of claim 7, wherein the air flow structure layer comprises tubular spacer fabric.
 14. The apparatus of claim 7, wherein the thermal insulation layer comprises a radiation cross-linked closed cell foam.
 15. A headgear apparatus comprising: a) a shell having an inner surface and an outer surface; b) an air flow structure coupled to the inner surface of the shell; c) a thermoelectric system configured to produce a stream of air, the thermoelectric system coupled to the shell and the air flow structure and comprising a housing having: i) at least one air inlet; ii) a first air outlet and a second air outlet; iii) a least one blower; iv) at least one thermoelectric heat pump disposed within the housing, between the air inlet and the air outlets; and v) a condensate wick disposed within the housing, below the blower and heat pump, the condensate wick configured to collect condensation formed by the heat pump and evaporate the collected condensation using the hot air produced by the heat pump; wherein the first air outlet provides the stream of cooled air to the air flow structure and the second air outlet vents hot air produced by the heat pump to outside the apparatus.
 16. The apparatus of claim 15, wherein there are a plurality of blowers and a plurality of heat pumps within the housing.
 17. The apparatus of claim 15, wherein the apparatus further comprises a thermal insulation layer disposed between the inner surface of the shell and the air flow structure.
 18. The apparatus of claim 15, wherein the thermoelectric system housing removably couples the shell.
 19. The apparatus of claim 15, wherein the apparatus further comprises an impact absorbing layer disposed between the inner surface of the shell and the air flow structure.
 20. The apparatus of claim 15, wherein the air flow structure layer comprises tubular spacer fabric. 